1. Field
This disclosure relates to the field of communications, and in particular to a harmonic distortion separation method, nonlinear character determination method and apparatus and a system.
2. Description of the Related Art
As continuous increase of a transmission rate of a communication system, a nonlinear character in the system becomes one of factors limiting the performance, therefore, much attention is paid to it. In various methods of dealing with a nonlinear character of a system, a necessary premise step is measuring and estimating the nonlinear character.
Currently, a commonly-used method is to first measure a nonlinear harmonic of a system to be measured or a device to be measured, then either directly use harmonic power to feature a nonlinear character (THD (total harmonics distortion) index of a device), or create a nonlinearity model, calculate a model coefficient according to the harmonic power, and determine the nonlinear character by using the model. Its advantage is being simple in measuring and wide in applicability. However, a problem exists in these methods that when a harmonic is measured, if a test signal inputted to the system to be measured or the device to be measured itself has a relatively large harmonic component (which is inevitable in measurement), a relatively large error will exist in the measured harmonic power.
It should be noted that the above description of the background is merely provided for clear and complete explanation of this disclosure and for easy understanding by those skilled in the art. And it should not be understood that the above technical solution is known to those skilled in the art as it is described in the background of this disclosure.